caddy-frontend/test: Prove that disabled-cookie-list does not work

Due to python2 dict handling the problem has been hidden, but smart order
of disabled-cookie-list setup exposed the problem.
17 jobs for master
Status Job ID Name Coverage
  External
running Cloudooo.UnitTest-Master

20802:50:32

failed ERP5.StandaloneDeploymentScriptTest-Debian.Buster

15:03:15

failed ERP5.StandaloneDeploymentScriptTest-Debian.Buster.Master

15:03:37

failed ERP5.StandaloneDeploymentScriptTest-Debian.Stretch

15:03:02

failed SlapOS-Master.StandaloneDeploymentScriptTest-Debian.Buster

15:03:00

passed SlapOS.Eggs.UnitTest-Master.Python2

03:31:48

passed SlapOS.Eggs.UnitTest-Master.Python3

03:29:21

passed SlapOS.SlapRunner.ResilienceTest-Master

03:39:02

failed SlapOS.SlapRunner.ResilienceTest-Master.ERP5

01:30:10

failed SlapOS.SoftwareReleases.IntegrationTest-Master.Python2

06:25:15

passed SlapOS.SoftwareReleases.IntegrationTest-Master.Python3

06:04:35

failed Wendelin.StandaloneDeploymentScriptTest-Debian.Buster

15:03:27

failed Wendelin.StandaloneDeploymentScriptTest-Debian.Buster.Master

15:03:17

failed Wendelin.StandaloneDeploymentScriptTest-Debian.Stretch

15:03:20

failed SlapOS.SlapRunner.ResilienceTest-Master.ERP5

01:30:41

failed SlapOS.SoftwareReleases.IntegrationTest-Master.Python2

02:33:56

failed SlapOS.SoftwareReleases.IntegrationTest-Master.Python3

06:47:59